Field of the Invention
This invention relates to a centrifugal separator for removing soot particles from exhaust gas of an internal combustion engine.
Description of Related Art
Exhaust gas produced from an internal combustion engine includes undesirable pollutants in the form of nitrogen oxide (NOx) and carbon monoxide (CO). In addition, the exhaust gas includes carbon particles, which are more prevalent in diesel engines. These particles, generally described herein as soot, have a size on the order of about 0.01 to 1.00 micron. Currently, exhaust gas recirculation (EGR) systems intentionally introduce exhaust gas into the air intake of the engine to reduce the amount of NOx produced in the combustion process. However, by doing so, the carbon particles are also introduced into the air intake, which not only causes reduced engine performance, but also negatively impacts electronic sensors that are used for controlling engine performance and pollution abatement equipment. It is desirable to reduce or eliminate these particles from the EGR gas prior to reintroduction into the air intake. Filtering systems exist to remove these objectionable particles from the exhaust gas. However, such systems are mechanical or require complex electronics, each of which is prone to failure over time. Other systems include particle filters which must be replaced frequently to avoid clogging.
Further aggravating the situation, control systems for pollution abatement equipment on commercial diesel trucks, for example, are programmed to reduce engine output when certain antipollution equipment is nonfunctional or functioning only at a minimally prescribed level. Since a significant portion of pollution abatement equipment is directed to removal of soot particles, a device is needed to provide such pollution abatement wherein the device is robust, effective, and has few or no movable parts.